For Kids, the Great Outdoors May Not Always Be So Great
In the study, Gauderman and colleagues performed lung capacity tests on more than 3,000 students living in and around Los Angeles each year for four years. Half of the students was in the fourth grade at the beginning of the study, one-quarter was in the seventh grade, and the remaining one-quarter was in the 10th grade.
While children living in the low-pollution counties north of Los Angeles showed normal lung function growth of around 12% a year, children living in the high-pollution communities lagged by about 1% per year, Gauderman says. By the end of the four-year study period, children living in the most polluted areas had a reduction of 3.4% in a measure that looks at lung capacity and a 5% reduction in a measure that accesses airflow in the lungs.
"Reductions of 3.4% and 5% do not seem like much, but one has to remember that we are talking about growing lungs," Gong says. "We don't know what the long-term effects of this delayed maturation will have on adult health."
Gauderman explains: "What happens with lung growth is that capacity will grow in females until about age 18, and in males until the early 20s. Then growth plateaus for about 10 years, and beginning in the late 20s both males and females start to lose function. These kids in the higher-pollution communities may be plateauing at a lower level, suggesting that they will have lower lung function as adults."
The USC researchers are still following the children who have not graduated from high school, and they plan to publish data after eight years of follow-up. They also hope to find funding to follow the group into adulthood, in an effort to document the long-term effects of air pollution on their lung function.